remove winner check

test/db_tests/match_test.dart

@@ -167,13 +167,6 @@ void main() {
         expect(match.id, testMatch.id);
         expect(match.name, testMatch.name);
         expect(match.createdAt, testMatch.createdAt);
-        if (match.winner != null && testMatch.winner != null) {
-          expect(match.winner!.id, testMatch.winner!.id);
-          expect(match.winner!.name, testMatch.winner!.name);
-          expect(match.winner!.createdAt, testMatch.winner!.createdAt);
-        } else {
-          expect(match.winner, testMatch.winner);
-        }
 
         // Group-Checks
         if (testMatch.group != null) {

test/db_tests/player_match_test.dart

@@ -214,8 +214,8 @@ void main() {
       'Adding the same player to separate matches works correctly',
       () async {
         final playersList = [testPlayer1, testPlayer2, testPlayer3];
-        final match1 = Match(name: 'Match 1', players: playersList);
-        final match2 = Match(name: 'Match 2', players: playersList);
+        final match1 = Match(name: 'Match 1', game: testGame, players: playersList);
+        final match2 = Match(name: 'Match 2', game: testGame, players: playersList);
 
         await Future.wait([
           database.matchDao.addMatch(match: match1),